I'm not finding a lot of people online who have talked about using the Sony RM-LVR1 or RM-LVR2 with cameras other than the Sony action cam, though supposedly it is also compatible with the alpha cameras (the A7s in particular is mentioned). It's inexpensive and relatively small and it seems like it could be sort of handy on a multi-camera shoot when I'm all alone (it'd save some running from tripod to tripod hitting record and stop buttons at the beginning and end of every take).

I ended up grabbing one because I was curious and because a local Best Buy had an open box one for $33.
Overall, it seems to work as expected and it's OK. Range is limited (only about 6 feet), but the thing that sucks more for me is that when the Sony Smart Remote app is running (needed connect to the smart remote), picture profiles aren't available which means no slog2. It'll end up being usable for me when I have a camera stuck to my car when driving in crazy places, but for a lot of my shoots, I prefer to have slog2 available.
Worth the $33, I think, but absolutely not worth it at $150!